JP2020142875A - Sheet feeder and image formation device - Google Patents

Abstract

To solve a problem of a bottom plate movement at the sheet feeder every time the imaging formation device returns to sleep while there is no paper in the sheet feeder, generating noise and slow determination of no paper.SOLUTION: A sheet feeder comprises a tray member such as paper tray 71 having a lifting member such as bottom plate 218 capable of being raised and lowered by loading sheets of paper P, etc., and being inserted and removed from the paper feed section 70, an insertion/extraction detection means 302 detecting when the tray member is pulled out of the paper feed section while the power is not supplied to the paper feed section, a sheet presence detection means such as a paper end sensor 212 detecting whether a sheet is present or absent on the lifting member, and a sheet presence storage means such as a non-volatile memory 217 storing the sheet presence or absence detected by the sheet presence detection means, when power is supplied to the paper feeding section, there is no sheet stored in the sheet presence storage means and the tray member is not used in the paper feeding section, controls the tray raising motor 206 so that the raising and lowering member does not operate if it is not pulled out of the tray.SELECTED DRAWING: Figure 12

Description

The present invention relates to a sheet feeding device and an image forming device.

Sheet feeding devices used in image forming devices such as copiers, printers, printing machines, and fax machines are known (see, for example, Patent Document 1). In the sheet feeding device described in Patent Document 1, the presence or absence of paper can be detected only when the bottom plate is at the position where the tray upper limit sensor is turned on (hereinafter referred to as “ON”).
Further, when it is detected that there is no paper, as described in claim 3 of the same document, the bottom plate is lowered to separate it from the paper feed roller and the paper end sensor, so that the power of the sheet feeding device is turned off / on ( After that (hereinafter referred to as "OFF / ON"), it was necessary to move the bottom plate to the position where the tray upper limit sensor is turned ON again to detect the presence or absence of paper. This detection of the presence or absence of paper is necessary because there is a possibility that the user is replenishing the paper while the power is off (hereinafter referred to as "OFF") even when the non-volatile state is stored in the non-volatile memory or the like. Is.

When the image forming apparatus goes to sleep, the power of the sheet feeding apparatus is turned off. When the image forming apparatus returns from the sleep state, the power of the sheet feeding apparatus is turned on. Therefore, every time the image forming apparatus returns to sleep when there is no paper in the sheet feeding device, the sheet feeding device operates the bottom plate, and there is a problem that an operation sound is generated and the determination of no paper is slow.

The present invention has been made in view of the above-mentioned circumstances, and every time the image forming apparatus returns to sleep when there is no paper in the sheet feeding device, the sheet feeding device causes a bottom plate operation to generate an operating noise. The purpose is to solve the problem of slow occurrence and slow confirmation of no paper.

In order to achieve the above object, the present invention detects that an elevating member capable of loading and lowering a sheet, a tray member capable of being inserted and removed from the device main body, and the tray member being inserted and removed from the device main body. A seat presence / absence detecting means for detecting the presence / absence of a seat on the elevating member, a seat presence / absence storage means for storing the seat presence / absence detected by the seat presence / absence detecting means, and the seat presence / absence storage means. The sheet feeding device does not raise the elevating member when there is no sheet stored in the means and the tray member is not pulled out from the apparatus main body in advance.

According to the present invention, it is possible to reduce the operating noise of the elevating member in the seat feeding device and to shorten the seatless confirmation time when the image forming apparatus returns to sleep in the state where the seat feeding device has no seat. it can.

It is a schematic whole block diagram of the image forming apparatus which concerns on one Embodiment of this invention. It is a figure which illustrates the functional structure of the image forming apparatus of FIG. It is a figure which illustrates the schematic structure around the paper tray of each paper feed part which concerns on Example 1. FIG. It is a figure which illustrates the schematic structure around the paper tray of each paper feed part which concerns on Example 1. FIG. It is a figure which illustrates the schematic structure around the paper tray of each paper feed part which concerns on Example 1. FIG. It is a block diagram which shows the main control structure of the paper feed part which concerns on Example 1. FIG. It is a figure explaining the operation of the paper feed part which concerns on Example 1. FIG. It is a figure explaining the operation of the paper feed part which concerns on Example 1. FIG. FIG. 5 is a plan view illustrating the position of the insertion / removal detecting means when the paper tray according to the first embodiment is set in the paper feeding unit. It is a top view which illustrates the position of the insertion / removal detection means when the paper tray which concerns on Example 1 is pulled out from a paper feed part. It is a figure explaining the structure and operation of the insertion / removal detection means which concerns on Example 1, and is the figure seen from the direction of the thick arrow of FIG. 9 and FIG. FIG. 5 is a flowchart illustrating a control operation at the start of power supply of the paper feed unit according to the first embodiment. It is a figure which illustrates the schematic structure around the paper tray of the paper feed device which concerns on Example 2. FIG. It is a figure which illustrates the schematic structure around the paper tray of the paper feed device which concerns on Example 2. FIG. It is a figure which illustrates the schematic structure around the paper tray of the paper feed device which concerns on Example 2. FIG. It is a block diagram which shows the main control structure of the paper feed device which concerns on Example 2. FIG. It is a figure explaining the operation of the paper feed device which concerns on Example 2. FIG. It is a figure explaining the operation of the paper feed device which concerns on Example 2. FIG. It is a flowchart explaining the control operation at the time of starting the power supply of the paper feed device which concerns on Example 2. FIG. It is a figure which shows the electric circuit structure of the insertion / removal detection means which concerns on modification 1. It is a figure which illustrates the schematic structure of the paper feed device which concerns on Example 3, and is the figure which shows the state which the front cover is opened. It is a figure which illustrates the schematic structure of the paper feed device which concerns on Example 3, and is the figure which shows the state which the front cover is closed. It is a perspective view which shows through the drive structure and the sensor structure of the paper feed device which concerns on Example 3. FIG. It is a block diagram which shows the main control structure of the paper feed device which concerns on Example 3. FIG. It is a block diagram which shows the main control structure of the paper feed device which concerns on Example 4. FIG.

Hereinafter, embodiments of the present invention including examples will be described in detail with reference to the drawings. As long as there is no risk of confusion, the components (members, components) and the like having the same function and shape, etc. in each embodiment will be described once and then the same reference numerals will be given to omit the description. In order to simplify the figures and explanations, even if the components should be represented in the figure, the components that do not need to be described in the figure may be omitted without notice. When a component of a published patent gazette or the like is cited and explained, the reference numeral thereof shall be shown in parentheses to distinguish it from that of each embodiment or the like.

An embodiment of the present invention will be described with reference to FIGS. 1 and 2.
First, with reference to FIG. 1, the overall configuration of the image forming apparatus according to the embodiment of the present invention will be described. FIG. 1 is a schematic overall configuration diagram of an image forming apparatus according to an embodiment of the present invention.
The image forming apparatus 100 includes a photoconductor 10, a charging apparatus 11, an exposure apparatus 12, a developing apparatus 13, an intermediate transfer belt 20, a secondary transfer roller 30, a fixing device 40, an automatic document feeder (ADF) 50, a reading device 51, and the like. To be equipped.

The image forming apparatus 100 includes a plurality of developing units including a photoconductor 10, a charging device 11, an exposure device 12, a developing device 13, and the like that form toner images of different colors, and is housed in a paper feeding unit 70. It is a multifunction device that prints and outputs a color image on paper P as an example of a state recording medium (hereinafter, simply referred to as “sheet”).

When printing an image on the paper P in the image forming apparatus 100, first, the charging apparatus 11 uniformly charges the surface of the rotating photoconductor 10, and the scanning apparatus 51 reads, for example, a document set in the ADF 50. The exposure apparatus 12 exposes the surface of the photoconductor 10 to form an electrostatic latent image based on the image data and the like. Next, the developing device 13 that houses the developer containing the toner inside develops the electrostatic latent image on the surface of the photoconductor 10 to form the toner image. The image forming apparatus 100 forms toner images of different colors in a plurality of developing units, and then superimposes and transfers the toner images on the rotating intermediate transfer belt 20.

The toner image transferred to the intermediate transfer belt 20 is conveyed from any one of the plurality of paper feeding units 70a to 70d at the secondary transfer unit between the intermediate transfer belt 20 and the secondary transfer roller 30. Secondary transfer is performed on paper P. The paper P on which the toner image is transferred is further conveyed, heated and pressurized by the fixing device 40, and discharged to the paper ejection tray 90 in a state where the toner image is fixed.

The image forming apparatus 100 has a supply means for supplying the paper P to be stored and a plurality of paper feeding units 70a to 70d as a sheet feeding device. Each paper feeding unit 70 (hereinafter, abbreviated by reference numeral a to d) is a paper tray 71 as a tray member for supplying the paper P, and a paper feeding roller 72 for supplying the paper P from the paper tray 71 to the transport path. The paper feed sensor 73 is provided as a supply detection means for detecting the paper P supplied from the paper tray 71 to the transport path. As shown in the figure, for example, a bypass tray 91 or the like for supplying the loaded paper P to the transport path may be provided as a paper feed unit.
The "device main body" of the present invention refers to a portion of the image forming apparatus 100 excluding the automatic document feeder (ADF) 50, the paper feeding unit 70, and the paper feeding device 101.

The paper feeding device 101 surrounded by a broken line in FIG. 1 is an example of a sheet feeding device, and instead of the paper feeding unit 70c and the paper feeding unit 70d, a tandem type paper tray as in the second embodiment described later. It may be a one-stage paper tray, or it may be a large-capacity paper feed tray (LCT) as in Examples 3 and 4 described later. The paper feed device 101 made of the large-capacity paper feed tray (LCT) of the fourth embodiment may be externally attached to the outside of the main body of the image forming device 100.

The paper P, which is fed one by one from the paper tray 71 by the paper feed roller 72, is provided by the rollers 75 to 78 on the downstream side of the plurality of paper feed units 70 in the transport path. It is transported toward 81. The transport roller 81 transports the paper P to a resist roller 35 provided further downstream.

A transport sensor 79 as a transport detection means is provided between the paper feed unit 70 and the transport roller 81 in the transport path. The transport sensor 79 detects the paper P transported along the transport path. When the manual feed tray 91 is provided as the paper feed unit, the transfer roller 81 and the transfer sensor 79 are provided on the downstream side of the plurality of paper feed units 70a to 70d and the manual feed tray 91 in the paper transfer path.

FIG. 2 is a diagram illustrating the functional configuration of the image forming apparatus of FIG. As shown in FIG. 2, the image forming apparatus 100 includes a paper feeding unit 70, an engine control unit 110, a fixing unit 120, an image forming unit 130, a controller control unit 140, an operation display unit 150, a network I / F unit 160, and a recording unit. It has a medium I / F part 170.

The paper feed unit 70 outputs the detection result of the paper P by the paper feed sensor 73 to the engine control unit 110. The engine control unit 110 has a storage unit 113. The engine control unit 110 controls the fixing unit 120, the image forming unit 130, and the like under the image forming conditions.

The storage unit 113 is, for example, a ROM, RAM, HDD, etc., and stores various programs, data used by the programs, and the like. The fixing unit 120 is a fixing device 40 of the image forming apparatus 100 shown in FIG. 1, and fixes a toner image on the paper P by heating and pressurizing the paper P conveyed between the heating roller and the pressure roller. ..

The image forming unit 130 has the photoconductor 10, the charging device 11, the developing device 13, and the like of the image forming apparatus 100, and transfers the toner image formed on the surface of the photoconductor 10 to the paper P. The controller control unit 140 controls each part of the image forming apparatus 100 and controls the operation display unit 150.

The operation display unit 150 includes various operation keys, for example, a display such as a liquid crystal display, an LED lamp, and the like. The operation keys are used for inputting operations necessary for using each function such as copying, printing, and scanning of the image forming apparatus 100, and operations for specifying the type of paper P. In addition, the display displays the content of the command input from the operation keys and various information notified to the user from the image forming apparatus 100.

The network I / F unit 160 is a peripheral having a communication function connected via a network such as a LAN (Local Area Network) or a WAN (Wide Area Network) constructed by a data transmission line such as a wired and / or wireless line. It is an interface between the device and the image forming apparatus 100.

The recording medium I / F unit 170 is an interface with the recording medium. The image forming apparatus 100 can read and / or write to the recording medium 171 via the recording medium I / F unit 170. The recording medium 171 includes a flexible disk, a CD, a DVD (Digital Versatile Disk), an SD memory card (SD Memory card), a USB memory (Universal Serial Bus memory), and the like.

(Example 1)
FIG. 3 is a diagram illustrating a schematic configuration around a paper tray of each paper feed unit according to the first embodiment. As described above, each of the paper feeding units 70 has the same configuration, and in the first embodiment, one of them will be described as a representative with reference to FIG. The paper feed unit 70 is provided with a paper tray 71 that can be inserted into and removed from the paper feed unit 70.
The paper tray 71 has a bottom plate 218 as an elevating member capable of loading and lowering paper. The paper tray 71 is configured so that it can be pulled out (pulled out) from the paper feeding unit 70 toward the front side of the paper surface shown in FIG. 3 and inserted (inserted) into the back side of the paper surface shown in FIG.

The paper feeding unit 70 is provided with a calling roller 203, a paper feeding roller 72, a separation roller 204, and a tray set detection switch 202. The calling roller 203 comes into contact with the uppermost surface of the paper bundle P loaded on the bottom plate 218 of the paper tray 71 to pull out the paper and perform a pick-up operation. The paper feeding roller 72 and the separating roller 204 separate and feed the sheets drawn by the calling roller 203 one by one by a cooperative action. The roller pair 75 conveys the sheets separated one by one to the downstream.
The tray set detection switch 202 is connected to the tray raising motor 206 shown in FIG. 4 described later, which is arranged on the paper feed unit 70 side when the paper tray 71 is inserted and set in the paper feed unit 70, and is connected to the bottom plate. It detects that the 218 is set so that it can be raised and lowered. In addition, instead of the separation roller 204, a separation pad or the like may be used as the separation member.

FIG. 4 is a diagram illustrating a schematic configuration around a paper tray of each paper feed unit according to the first embodiment. As shown in FIG. 4, the paper feeding unit 70 includes a tray raising motor 206 that raises the bottom plate 218 of the paper tray 71, a feeding motor 207 that rotationally drives the calling roller 203 and the feeding roller 72, and a drawing described later. A control board 230 on which the control means 216 shown in 6 is mounted is provided. The tray raising motor 206 and the paper feeding motor 207 are motors capable of rotating (that is, rotating) in both forward and reverse directions.

FIG. 5 is a diagram illustrating a schematic configuration around a paper tray of each paper feed unit according to the first embodiment. As shown in FIG. 5, the paper feeding unit 70 has a paper end sensor 212 that detects the presence or absence of paper on the bottom plate 218 of the paper tray 71, and an upper limit position of the bottom plate 218 or an upper limit position of the paper loaded on the bottom plate 218. The tray upper limit sensor 214 for detecting the above and the paper feed pickup solenoid 215 for performing the paper feed pickup operation of the calling roller 203 are provided.

FIG. 6 is a block diagram showing a main control configuration of the paper feed unit according to the first embodiment. As shown in FIG. 6, the control means 216 is composed of, for example, a microcomputer equipped with a CPU, ROM, RAM, and the like. A tray set detection switch 202, a paper end sensor 212, a tray upper limit sensor 214, and an insertion / removal detection switch 302-3 are electrically connected to the input port side of the control means 216. Further, a tray raising motor 206 and a non-volatile memory 217 whose storage operation is maintained even when power is not supplied are electrically connected to the output port side of the control means 216.

The CPU has a calculation function, a control function, and a timer function, and is based on each signal from the tray set detection switch 202, the paper end sensor 212, the tray upper limit sensor 214, and the insertion / removal detection switch 302-3, and the tray rise motor 206. And control the non-volatile memory 217. In the ROM, a program for exerting the control function of the CPU (for example, a program represented by a flowchart shown in FIG. 12 or the like described later which can be called by the CPU) and fixed data are stored in advance. The RAM temporarily stores various data input / output to / from the CPU.

7 and 8 are views for explaining the operation of the paper feed unit according to the first embodiment. An operation when the paper tray 71 is set in the paper feeding unit 70 will be described with reference to FIGS. 6 to 8.
When the paper tray 71 is set in the paper feed unit 70, the bottom plate 218 is in the position shown in FIG. 7. First, when the tray set detection switch 202 detects the set of the paper tray 71, the control means 216 sets the paper presence / absence stored in the non-volatile memory 217 to the paper presence / absence unknown state. Further, when the set of the paper tray 71 is detected, the control means 216 drives the tray raising motor 206 to raise the bottom plate 218.

When the paper P is loaded on the bottom plate 218, as shown in FIG. 8, the upper surface of the paper P pushes up the calling roller 203, so that the tray upper limit sensor 214 is turned on, and the control means 216 is based on this signal. The tray raising motor 206 is stopped. In this state, the upper surface of the paper P pushes up the filler portion (not shown) of the paper end sensor 212, and the paper end sensor 212 detects the presence of paper. Therefore, the control means 216 determines that there is paper.
At this time, since the presence or absence of paper is detected by pushing up the filler portion, false detection of the presence or absence of paper does not occur even when glossy paper or the like is used.
The filler portion is a component of the paper end sensor 212 and swings in conjunction with the mechanical detection operation of the presence or absence of paper to open the light passage path of the paper end sensor 212 composed of a light transmissive sensor. It is a member that shields or shields.

When the paper P is not loaded on the bottom plate 218, the bottom plate 218 itself pushes up the calling roller 203 to turn on the tray upper limit sensor 214, and the control means 216 stops the tray raising motor 206 based on this signal. The filler portion of the paper end sensor 212 on the bottom plate 218 (not shown) penetrates a hole (not shown) at a position corresponding to the paper end sensor 212 on the bottom plate 218, so that the paper end sensor 212 has no paper. It is designed to detect. That is, the control means 216 determines that there is no paper by penetrating the hole (not shown) without pushing up the filler portion of the paper end sensor 212.

FIG. 9 is a plan view illustrating the position of the insertion / removal detecting means 302 when the paper tray 71 according to the first embodiment is set in the paper feed unit 70, and FIG. 10 shows the paper tray 71 according to the first embodiment as the paper feed unit. It is a top view which illustrates the position of the insertion / removal detection means 302 when it is pulled out from 70. FIG. 11 is a diagram for explaining the configuration and operation of the insertion / extraction detection means 302 according to the first embodiment, and is a view seen from the direction of the thick arrow in FIGS. 9 and 10.
The insertion / removal detecting means 302 detects that the paper tray 71 is pulled out from the paper feeding unit 70 while the power is not supplied to the paper feeding unit 70.

As shown in FIGS. 9, 10 and 11 (a) to 11 (d), the paper tray 71 has a stopper 302-2, a fulcrum pin 302-5, a spring seat 302-6, and a compression spring 302-. 7 is arranged at a predetermined portion. The stopper 302-2 is a member long in the vertical direction in FIGS. 11 (a) to 11 (d), and the lower portion of the stopper 302-2 is provided via a fulcrum pin 302-5 provided on the paper tray 71. , It is supported by the paper tray 71 so as to be swingable within a predetermined angle range. An inclined surface 302-2a is formed on the upper part of the stopper 302-2.

The spring seat 302-6 is fixed at a predetermined position on the paper tray 71. A compression spring 302-7 is mounted between the stopper 302-2 near the lower side of the fulcrum pin 302-5 and the spring seat 302-6. In the state before the paper tray 71 is set in the paper feed unit 70, the stopper 302-2 is positioned in the substantially upright state shown in FIG. 11A by the urging force of the compression spring 302-7. The movement of swinging clockwise is regulated by the stopper member (not shown).

On the other hand, as shown in FIG. 11A, the paper feed unit 70 has the insertion / removal detection pin push-up unit 301 and the insertion / removal detection pin 302- in a state before the paper tray 71 is set in the paper feed unit 70. 1. The insertion / removal detection switch 302-3 is arranged at the position shown in the figure of the paper feed unit 70. The insertion / removal detection pin 302-1 is supported by the paper feed unit 70 so as to be swingable by its own weight within a range of a predetermined angle around the fulcrum pin 302-4 provided at the right end portion in the drawing.

As shown in FIG. 11A, immediately after the paper tray 71 is set in the paper feed unit 70, the insertion / removal detection pin push-up unit 301, the insertion / removal detection pin 302-1, the stopper 302-2, and the insertion / removal detection switch 302 The positional relationship of -3 is as shown in the figure.
As shown in FIG. 11B, after the paper tray 71 is set in the paper feed section 70, the paper P is inserted in conjunction with the upper surface of the paper P pushing up the calling roller 203 as the bottom plate 218 of the paper tray 71 rises. The detachment detection pin pushing-up portion 301 is raised, and the insertion / removal detection pin 302-1 is pushed up together with the insertion / removal detection pin pushing-up portion 301. At this time, in the figure of the insertion / removal detection pin 302-1, the left end portion and the inclined surface 302-2a of the stopper 302-2 are engaged with each other, so that the stopper 302 resists the urging force of the compression spring 302-7. Swing -2 to the left.

Further, as shown in FIG. 11C, when the insertion / removal detection pin pushing portion 301 is pushed up and the tray upper limit sensor 214 is turned on, the control means 216 stops the tray raising motor 206, and the raising of the bottom plate 218 is stopped. At this time, the insertion / removal detection pin 302-1 rides on the stopper 302-2, and the stopper 302-2 is returned to the right by the urging force of the compression spring 302-7. At this time, the position of the stopper 302-2 is the same as that shown in FIG. 11 (a). Then, the insertion / removal detection pin 302-1 presses (ON) the insertion / removal detection switch 302-3.

In the operations of FIGS. 11C to 11D, when all the paper P is fed to the image forming portion side of the image forming apparatus 100, the filler portion of the paper end sensor 212 loses the support by the paper P. The absence of paper is detected by penetrating the holes at the corresponding positions of the bottom plate 218. The control means 216 receives a signal from the paper end sensor 212 regarding the absence of paper, determines that there is no paper, and drives the tray raising motor 206 in the direction of lowering the bottom plate 218 to lower the bottom plate 218. The control means 216 stops the tray raising motor 206 after a certain period of time has elapsed after the tray upper limit sensor 214 is turned off. The calling roller 203 pushed up by the bottom plate 218 is lowered by a certain amount as the bottom plate 218 is lowered, and then stops in a state of being separated from the bottom plate 218.

At this time, as shown in FIG. 11D, the insertion / removal detection pin pushing-up unit 301 descends in conjunction with the calling roller 203, but the insertion / removal detection switch 302-3 is pressed by the insertion / removal detection pin 302-1. Will remain. Further, the control means 216 stores the non-volatile state in the non-volatile memory 217 when the paper end sensor 212 detects that there is no paper.

When the paper tray 71 is pulled out from the paper feed unit 70, as shown in FIG. 11 (e), the stopper 302-2 is pulled out together with the paper tray 71, so that the insertion / removal detection pin 302-1 is the stopper 302. It loses the support of -2, swings counterclockwise under its own weight, descends, and rides on the insertion / detachment detection pin pushing-up portion 301. Since the insertion / removal detection pin 301-1 is lowered, the insertion / removal detection switch 302-3 is in the non-pressed state (OFF state).

Therefore, when the paper tray 71 is pulled out, it is in the pre-pulled state shown in FIG. 11 (e), and when the paper tray 71 is set after that, it is in the state shown in FIG. 11 (a). If it is not pressed, it means that the paper tray 71 has been pulled out in advance, and it can be seen that the paper tray 71 has been set after that.

The possible operating states of the insertion / removal detection means 302 of the first embodiment are summarized as follows.
That is, the insertion / removal detecting means 302 is in the "first state" according to the present invention when the bottom plate 218 is raised, and is in the "second state" according to the present invention when the paper tray 71 is pulled out from the paper feeding unit 70. Is.

Further, the "first state" according to the present invention is a state in which the insertion / removal detection switch 302-3 constituting the insertion / removal detection means 302 is pressed, and the "second state" according to the present invention is the insertion / removal detection switch. 302-3 is not pressed.

FIG. 12 is a flowchart illustrating a control operation at the start of power supply of the paper feed unit 70 according to the first embodiment.
In the insertion / removal detection means 302 having the above-mentioned insertion / removal detection switch 302-3 and the paper feed unit 70 having the control configuration shown in FIG. 6, the control means 216 raises and lowers the bottom plate 218 according to the flowchart shown in FIG. 12 at the start of power supply. Take control.
First, in step S1, the presence or absence of paper P in the paper feed unit 70 is confirmed. When the paper end sensor 212 detects that there is no paper, the control means 216 stores the non-volatile state in the non-volatile memory 217. Therefore, in step S1, yes (hereinafter, described as “YES” in the flowchart) is selected.
In step S1, if the control means 216 does not detect the absence of paper by the paper end sensor 212 but detects the presence of paper, the process proceeds to step S4 and no (hereinafter, described as "NO" in the flowchart). Is selected, and the control means 216 starts the operation of the bottom plate to raise the bottom plate 218 by driving the tray raising motor 206.

Next, in step S2, it is confirmed whether or not the paper tray 71 has been pulled out before the power is turned on. If the power supply to the paper feed unit 70 is started without pulling out the paper tray 71 while the power is not supplied, yes is selected because the insertion / removal detection switch 302-3 is kept pressed. .. Then, the process proceeds to step S3, and the bottom plate 218 can be prevented from being raised by assuming that the paper tray 71 does not operate.

If the paper tray 71 is pulled out before the power is turned on in step S2, no is selected because the insertion / removal detection switch 302-3 is not pressed, and the process proceeds to step S4 described above to push the bottom plate 218. The operation of the bottom plate to be raised is started.

As described above, according to the above-described first embodiment and the first embodiment, when the image forming apparatus returns to sleep (power supply starts for the paper feed unit) after the paper runs out in the paper feed unit, the paper feed unit The operation noise of the bottom plate can be reduced, and the paperless confirmation time can be shortened.

Here, the techniques disclosed in the prior art examples will be described. As an example of the prior art, for example, as described in Japanese Patent Application Laid-Open No. 2005-145691, in a configuration in which the presence / absence of paper can be detected regardless of the position of the bottom plate by using a reflective sensor for detecting the presence / absence of paper, the above background The problem described in the technical column does not occur. However, in the case of glossy paper or preformatted paper, a new problem of erroneously detecting the presence or absence of paper occurs.

(Example 2)
FIG. 13 is a diagram illustrating a schematic configuration around a paper tray 71 of the paper feeding device 101 according to the second embodiment. As described above with reference to FIG. 1, the paper feeding device 101 has a one-stage tandem type paper tray 71 surrounded by a broken line in FIG. The paper tray 71 has a handle for operation as in the first embodiment, has a structure that can be inserted and removed from the paper feeding device 101, and has a bottom plate 218 as an elevating member that can load and lower paper.
The paper tray 71 of the second embodiment is different from the bottom plate 218 of the paper tray 71 of the first embodiment in that the bottom plate 218 loads a larger number of sheets and moves up and down while maintaining a substantially horizontal state. However, they are considered to be functionally the same and will be described with the same reference numerals.
As shown in FIG. 13, the paper feeding device 101 is provided with a calling roller 203, a paper feeding roller 72, a separation roller 204, a roller pair 75, and the like, as in the first embodiment.

FIG. 14 is a diagram illustrating a schematic configuration around a paper tray of the paper feed device 101 according to the second embodiment.
The paper feed device 101 is provided with a tray set detection switch 202, a tray raising motor 206, and a paper feed motor 207 that rotationally drives the calling roller 203 and the paper feed roller 72, as in the first embodiment. .. Further, the paper feeding device 101 is provided with a control board 230A on which the control means 216A shown in FIG. 16 described later is mounted.

FIG. 15 is a diagram illustrating a schematic configuration around a paper tray of the paper feed device 101 according to the second embodiment. As shown in FIG. 15, the paper feeding device 101 has a paper end sensor 212 for detecting the presence or absence of paper on the bottom plate 218 of the paper tray 71, and an upper limit position of the bottom plate 218 or on the bottom plate 218, as in the first embodiment. A tray upper limit sensor 214 for detecting the upper limit position of the loaded paper and a paper feed pickup solenoid 215 for performing a paper feed pickup operation of the calling roller 203 are provided. Further, the paper feed device 101 is provided with a tray lower limit sensor 224 that detects the lower limit position of the bottom plate 218.

FIG. 16 is a block diagram showing a main control configuration of the paper feeding device 101 according to the second embodiment.
Compared with the control means 216 of the first embodiment, the control means 216A mainly removes the non-volatile memory 217 connected to the output port side and newly connects the tray lower limit sensor 224 to the input port side. Is different.

That is, the tray set detection switch 202, the paper end sensor 212, the tray upper limit sensor 214, the tray lower limit sensor 224, and the insertion / removal detection switch 302-3 are electrically connected to the input port side of the control means 216A. Further, a tray raising motor 206 is electrically connected to the output port side of the control means 216A. The tray raising motor 206 of the second embodiment is composed of, for example, a stepping motor driven by a drive pulse input.

The control means 216A moves the bottom plate 218 up and down based on the signal for detecting the set of the paper tray 71 from the tray set detection switch 202 and the paper presence / absence signal on the bottom plate 218 from the paper end sensor 212. It has a function of controlling the tray raising motor 206.

The control means 216A is based on signals from the tray set detection switch 202, the paper end sensor 212, the tray upper limit sensor 214, the tray lower limit sensor 224, and the insertion / removal detection switch 302-3, and is used to supply paper to the paper feed device 101 when power is supplied. The tray raising motor 206 is operated so that the first operation is performed when the tray 71 is not pulled out from the paper feed device 101 and the second operation is performed when the paper tray 71 is pulled out from the paper feed device 101. It has a function to control.

Here, the first operation is an elevating operation of the bottom plate 218 for detecting the presence or absence of paper on the bottom plate 218, and the second operation is the detection of the remaining amount of paper on the bottom plate 218 and the bottom plate 218. This is an elevating operation of the bottom plate 218 for detecting the presence or absence of the upper paper.

17 and 18 are views for explaining the operation of the paper feeding device 101 according to the second embodiment. An operation when the paper tray 71 is set in the paper feeding device 101 will be described with reference to FIGS. 16 to 18.
When the paper tray 71 is set in the paper feeding device 101, the bottom plate 218 is in the position shown in FIG. When the paper tray 71 is set in the paper feed device 101, the tray set detection switch 202 is pressed, and the state of the tray lower limit sensor 224 is confirmed by the control means 216A. When the tray lower limit sensor 224 is OFF, the control means 216A drives the tray raising motor 206 in the direction in which the bottom plate 218 is lowered, and stops the tray raising motor 206 when the tray lower limit sensor 224 is turned ON. When the tray lower limit sensor 224 is ON, the control means 216A does not drive the tray raising motor 206 in the direction in which the bottom plate 218 is lowered.
Next, the control means 216A drives the tray raising motor 206 in the direction in which the bottom plate 218 rises, and the bottom plate 218 rises.

When the paper P is set on the bottom plate 218, as shown in FIG. 18, the upper surface of the paper P pushes up the calling roller 203, so that the tray upper limit sensor 214 is turned on, and the control means 216A is based on this signal. The ascending motor 206 is stopped. In this state, the filler portion of the paper end sensor 212 is pushed up by the upper surface of the paper P, and the paper end sensor 212 detects the presence of paper, so that the control means 216A determines that there is paper. The control means 216A counts the drive pulses of the tray raising motor 206 while driving the tray raising motor 206 in the direction in which the bottom plate 218 rises, and calculates the load capacity of the paper P from the number of pulses.

When the paper P is not loaded on the bottom plate 218, the bottom plate 218 itself pushes up the calling roller 203 to turn on the tray upper limit sensor 214, and the control means 216A stops the tray raising motor 206 based on this signal. Similar to the first embodiment, a hole (not shown) is opened on the bottom plate 218 at a position corresponding to the filler portion of the paper end sensor 212, and the filler portion of the paper end sensor 212 is not pushed up and the hole is formed. By penetrating through, the control means 216A determines that there is no paper.

FIG. 19 is a flowchart illustrating a control operation at the start of power supply of the paper feeding device 101 according to the second embodiment.
In the insertion / removal detection means 302 having the above-mentioned insertion / removal detection switch 302-3 and the paper feed device 101 having the control configuration shown in FIG. 16, the control means 216A raises and lowers the bottom plate 218 according to the flowchart shown in FIG. 19 at the start of power supply. Take control. In the flowchart of FIG. 19, the tray upper limit sensor 214 and the tray lower limit sensor 224 are simply described as an upper limit sensor and a lower limit sensor.
When the power supply of the paper feed device 101 is started without pulling out the paper tray 71 while the power is not supplied when there is no paper P in the paper feed device 101, first, in step S11, the control means 216A is the paper end sensor. When the lack of paper is detected by 212, the bottom plate 218 is lowered to turn off the tray upper limit sensor 214. Therefore, since the state of the tray upper limit sensor 214 is OFF, yes is selected.

Next, in step S12, it is confirmed whether or not the paper tray 71 has been pulled out before the power is turned on. When the power supply of the paper feed device 101 is started without pulling out the paper tray 71 while the power is not supplied, yes is selected because the insertion / removal detection switch 302-3 is kept pressed. ..

Next, in step S13, the control means 216A drives the tray raising motor 206 in the direction in which the bottom plate 218 rises, waits until the tray upper limit sensor 214 is turned ON in step S14, and when the tray upper limit sensor 214 is turned ON, in step S15. The tray raising motor 206 is stopped. As a result, the ascending of the bottom plate 218 is stopped.

Then, the process proceeds to step S16, and yes is selected because there is no paper P in the paper feed device 101. In step S17, the control means 216A drives the tray raising motor 206 in the direction in which the bottom plate 218 descends, waits until the set time elapses in step S18, stops the tray raising motor 206 in step S19, and ends a series of operations. To do.

Further, if the power supply of the paper feed device 101 is started after the paper tray 71 is pulled out while the power is not supplied when there is no paper P in the paper feed device 101, no is selected in step S12. , Step S21 to step S27 → A → step S17 to step S19.

Further, when the paper P is present in the paper feed device 101 and the power supply of the paper feed device 101 is started without pulling out the paper tray 71 while the power is not supplied, no is selected in step S11, and the step S11. It passes through the operation flow of S20 to S28.

As described above, according to the above-described first embodiment and the second embodiment, the power supply of the paper feed device 101 is performed without the paper tray 71 being pulled out while the power is not supplied in the state where the paper feed device 101 does not have the paper P. When it is started (in the case of steps S11 to S19), the amount of movement of the bottom plate 218 can be reduced as compared with other cases, and the operation of the bottom plate at the start of power supply can be completed in a short time.

(Modification example 1)
A modified example 1 different from the insertion / removal detecting means of the first and second embodiments will be described. FIG. 20 is a diagram showing an electric circuit configuration of the insertion / removal detection means according to the first modification.
As shown in FIG. 20, the circuit configuration of the insertion / removal detection means 390 according to the first modification is a switch that can be switched between the power supply voltage terminal 410, the ground voltage terminal 420, and the power supply voltage terminal 410 and the ground voltage terminal 420. It has an element 430 and a capacitor element 440 connected to the switch element 430. A DC voltage is applied to the power supply voltage terminal 410 as a power supply voltage Vcc via a diode. The tray insertion / removal detection switch 400 is configured by the power supply voltage terminal 410, the ground voltage terminal 420, and the switch element 430.

In the first and second embodiments, when the bottom plate 218 or the paper P on the bottom plate 218 is in the upper limit position and the calling roller 203 is pushed up, the tray insertion / removal detection switch 400 is in the state shown in FIG. 20A. When the paper tray 71 is pulled out, the tray insertion / removal detection switch 400 is in the state shown in FIG. 20B. At other times, the tray insertion / removal detection switch 400 is in the state shown in FIG. 20 (c).

When the power is supplied to the paper feed device 101 in the state of FIG. 20A, the capacitor C of the capacitor element 440 is charged with an electric charge, so that the potential of the insertion / removal detection signal becomes equal to or higher than a predetermined level. When the power is not supplied to the paper feed device 101 in the state of FIG. 20A, the electric charge of the capacitor C is neither charged nor discharged, so that the potential of the insertion / removal detection signal does not change.

In the state of FIG. 20B, the electric charge is discharged to the capacitor C regardless of whether or not the power is supplied to the paper feed device 101, so that the potential of the insertion / removal detection signal becomes the GND (ground / ground) level.
In the state of FIG. 20C, the electric charge of the capacitor C is neither charged nor discharged regardless of whether or not the power is supplied to the paper feeding device 101, so that the potential of the insertion / removal detection signal does not change.

According to the control described in the first and second embodiments, the state shown in FIG. 20A is obtained during power supply, so that the capacitor C is charged with an electric charge. After that, regardless of whether power is supplied or not, if the paper tray 71 is pulled out, the state shown in FIG. 20B is obtained, and the potential of the insertion / removal detection signal becomes the GND level. As described above, the control means 216 or 216A composed of a CPU or the like detects the presence / absence of insertion / removal (insertion / removal) of the paper tray 71 that occurs while the power is not supplied by reading the potential state of the insertion / removal detection signal.

That is, the "first state" according to the present invention is a state in which the switch element 430 is connected to the power supply voltage terminal 410 and the capacitor C is charged with the electric charge of the power supply voltage Vcc. The "second state" according to the present invention is a state in which the switch element 430 is connected to the ground voltage terminal 420 and the electric charge of the capacitor C is discharged to the ground voltage terminal 420.

(Modification 2)
A modified example 2 different from the insertion / removal detection pin pushing-up portion 301 of the insertion / removal detection means 302 according to the first and second embodiments will be described.
When the paper tray 71 is set in the paper feed device 101 of the paper feed unit 70 and the set of the paper tray 71 is detected by the tray set detection switch 202, the control means 216 or 216A drives the paper feed pickup solenoid 215. The paper feed pickup solenoid 215 is interlocked with the insertion / removal detection pin push-up unit 301, and when the paper feed pickup solenoid 215 is pulled, the insertion / removal detection pin push-up unit 301 is shown in FIGS. 11 (a) → 11 (b) → FIG. It moves as in 11 (c), pushes up the insertion / removal detection pin 302-1, and rides on the stopper 302-2.

That is, in the second modification, the insertion / removal detecting means 302 is in the "first state" according to the present invention when the paper tray 71 is inserted into the paper feeding unit 70, and when the paper tray 71 is pulled out from the paper feeding unit 70, the present It is a configuration that becomes the "second state" according to the invention.

(Modification 3)
A modification 3 which is different from the insertion / removal detection pin pushing-up portion 301 of the insertion / removal detection means 302 in the first and second embodiments will be described.
When the paper tray 71 is set in the paper feed device 101 of the paper feed unit 70 and the tray set detection switch 202 detects the set of the paper tray 71, the control means 216 or 216A sets the paper feed motor 207 in the direction opposite to the paper feed direction. Drive a certain amount to. The paper feed motor 207 is interlocked with the insertion / removal detection pin push-up unit 301 via a one-way clutch (not shown), and when the paper feed motor 207 is driven in the direction opposite to the paper feed direction, the insertion / removal detection pin push-up unit 301 is shown in FIG. It moves as shown in 11 (a) → FIG. 11 (b) → FIG. 11 (c), pushes up the insertion / removal detection pin 302-1, and rides on the stopper 302-2.

That is, in the third modification, the insertion / removal detecting means 302 is in the "first state" according to the present invention when the paper tray 71 is inserted into the paper feeding unit 70, and when the paper tray 71 is pulled out from the paper feeding unit 70, the present It is a configuration that becomes the "second state" according to the invention.

(Modification example 4)
A modified example 4 different from the insertion / removal detection pin pushing portion 301 of the insertion / removal detection means 302 in the first and second embodiments will be described.
When the control means 216 or 216A drives the paper feed motor 207 in the paper feed direction for feeding the paper P, the paper feed motor 207 is interlocked with the insertion / removal detection pin push-up unit 301 via a torque limiter (not shown). When the paper feed motor 207 is driven in the paper feed direction, the insertion / removal detection pin push-up unit 301 moves as shown in FIGS. 11 (a) → 11 (b) → 11 (c), and the insertion / removal detection pin 302-1 Push up and ride on the stopper 302-2.

That is, in the modified example 4, when the calling roller 203 and the paper feeding roller 72 feed the paper P, the insertion / removal detecting means 302 is in the “first state” according to the present invention, and the paper tray 71 is the paper feeding unit. It is a configuration that becomes the "second state" according to the present invention when it is pulled out from 70.

(Example 3)
A third embodiment will be described with reference to FIGS. 21 to 24 when the paper feed device 101 shown in FIG. 1 is a large capacity paper feed tray (LCT). FIG. 21 is a diagram illustrating a schematic configuration of the paper feed device 101 according to the third embodiment, showing a state in which the front cover is opened, and FIG. 22 illustrates a schematic configuration of the paper feed device 101 according to the third embodiment. It is a figure which shows the state which the front cover is closed. FIG. 23 is a perspective view showing through the drive configuration and the sensor configuration of the paper feed device 101 according to the third embodiment, and FIG. 24 is a block diagram showing a main control configuration of the paper feed device 101 according to the third embodiment.
Compared with the paper feeding unit 70 of the first embodiment, the paper feeding device 101 of the third embodiment removes the removable paper tray 71 and replaces the paper tray 71 with an opening / closing member that can be opened and closed with respect to the paper feeding device 101. The main difference is that the front cover 225 is used as the front cover 225 and the open / close detection means 302 is used instead of the insertion / removal detection means 302.
In the paper feeding device 101 of the third embodiment, paper can be replenished to the bottom plate 218 with the front cover 225 open. The bottom plate 218 as an elevating member of the third embodiment should also be called a paper feed table that can be elevated while maintaining a substantially horizontal state, and can be elevated by loading at least 1000 sheets of paper P.

The open / close detecting means 302 detects that the front cover 225 is opened (opened) while the power is not supplied to the paper feeding device 101. The front cover 225 has a stopper 302-2, a fulcrum pin 302-5, a spring seat 302-6, and a compression spring 302 similar to those arranged on the paper tray 71 described with reference to FIGS. 9 to 11. -7 is arranged at a predetermined portion.

On the other hand, in the paper feed device 101, the "open / close detection pin push-up unit 301", which is substantially the same as the "insertion / removal detection pin push-up unit 301" as shown in FIG. The "open / close detection pin 302-1" which is substantially the same as the "pin 302-1" and the "open / close detection switch 302-3" which is substantially the same as the "insertion / removal detection switch 302-3" are arranged. ing.

In the third embodiment, if "opening / closing of the front cover 225" is read instead of "insertion / removal of the paper tray 71" of the first embodiment, the open / close detecting means 302 is the insertion / removal detecting means 302 shown in FIG. 11 of the first embodiment. Since it can be seen that the configuration is substantially the same as that of the above, the same reference numerals are used in the third embodiment. Further, since the insertion / removal detection switch 302-3 that constitutes the insertion / removal detection means 302 of the first embodiment has substantially the same configuration as the open / close detection switch 302-3 of the third embodiment, the same reference numerals are given in the third embodiment. It will be used.
Those skilled in the art can understand the configuration and operation of the open / close detection means 302 in the third embodiment by reading as follows in the configuration and operation of the insertion / removal detection means 302 of the first embodiment shown in FIGS. 9 to 11. It can be implemented, so it will be omitted. That is, "insertion / removal of the paper tray 71" is read as "open / close of the front cover 225", "insertion / removal detection means 302" is read as "open / close detection means 302", and "insertion / removal detection pin push-up unit 301" is "open / close detection". Read "pin push-up part 301", read "insertion / removal detection pin 302-1" as "open / close detection pin 302-1", and read "insertion / removal detection switch 302-3" as "open / close detection switch 302-3". Just do it.

Therefore, when the front cover 225 is opened (opened) instead of pulling out the paper tray 71, the pre-opened state shown in FIG. 11 (e) is obtained, and then, instead of setting the paper tray 71, the front cover is opened. When the 225 is closed, the state shown in FIG. 11A is obtained. Therefore, if the open / close detection switch 302-3 is not pressed at the start of power supply, the front cover 225 is opened (opened) in advance, and then. You can see that it was closed. As described above, those skilled in the art can understand that the opening / closing detecting means 302 has substantially the same configuration as the insertion / removal detecting means 302 of the first embodiment.

As shown in FIGS. 21 to 23, a front cover switch 226 for detecting the open / closed state of the front cover 225 is provided on the paper feed device 101 side. As shown in FIG. 21, when the front cover 225 is opened with respect to the paper feed device 101, the front cover switch 226 is not pressed and the front cover switch 226 is turned off. As shown in FIGS. 22 and 23, when the front cover 225 is closed with respect to the paper feed device 101, the front cover switch 226 is pressed to turn on the front cover switch 226.

As shown in FIG. 22, the paper feeding device 101 includes a paper feeding motor 207 that rotationally drives the calling roller 203 and the paper feeding roller 72, a tray raising motor 206 that raises and lowers the bottom plate 218, and a paper feeding pickup of the calling roller 203. A paper feed pickup solenoid 215 for operating the paper feed pickup solenoid 215 is arranged.
Further, the paper feed device 101 includes a paper end sensor 212 that detects the presence or absence of paper on the bottom plate 218, and a tray upper limit sensor 214 that detects the upper limit position of the bottom plate 218 or the upper limit position of the paper loaded on the bottom plate 218. A tray lower limit sensor 224 that detects the lower limit position of the bottom plate 218 is arranged. Further, the paper feeding device 101 is also provided with a control board (not shown) on which the control means 216B shown in FIG. 24, which will be described later, is mounted.

The operation when the front cover 225 is closed will be described. The bottom plate 218 is in the position shown in FIG. 23 when the front cover 225 is closed. When the front cover 225 is closed, the front cover switch 226 is pressed and the front cover switch 226 is turned on. Based on the ON signal of the front cover switch 226, the control means 216B drives the tray raising motor 206 in the direction in which the bottom plate 218 rises, so that the bottom plate 218 rises.
When the paper P is set on the bottom plate 218, the tray upper limit sensor 214 is turned on by the upper surface of the paper P pushing up the calling roller 203, and is controlled based on this signal, as shown in FIG. 18 of the second embodiment. Means 216B stops the tray lift motor 206. In this state, the filler portion of the paper end sensor 212 is pushed up by the upper surface of the paper P, and the control means 216B detects the presence of paper. While the control means 216B is driving the tray raising motor 206 in the direction in which the bottom plate 218 is raised, the control means 216B counts the driving pulses of the tray raising motor 206 and calculates the load capacity of the paper P from the number of pulses.

When the paper P is not set on the bottom plate 218, the bottom plate 218 itself pushes up the calling roller 203 to turn on the tray upper limit sensor 214, and the control means 216B stops the tray raising motor 206 based on this signal. There is a hole on the bottom plate 218 at the position corresponding to the filler part of the paper end sensor 212, and the filler part of the paper end sensor 212 is not pushed up and penetrates the hole, so that the control means 216B determines that there is no paper. To do.

As shown in FIG. 24, the control configuration of the paper feed device 101 according to the third embodiment uses the control means 216B instead of the control means 216 as compared with the control configuration of the first embodiment shown in FIG. The main difference is that the front cover switch 226 is used instead of the tray set detection switch 202, and the open / close detection switch 302-3 is used instead of the insertion / removal detection switch 302-3.
In the control means 216B, when the power is supplied to the paper feed device 101, there is no paper stored in the non-volatile memory 217, and the front cover 225 is opened based on the signal from the open / close detection switch 302-3 ( It has a function of controlling the tray raising motor 206 so that the bottom plate 218 does not operate when it is not opened).

The possible operating states of the open / close detection means 302 of the third embodiment are summarized as follows. That is, the open / close detection means 302 is configured to be in the "first state" according to the present invention when the bottom plate 218 is raised, and to be in the "second state" according to the present invention when the front cover 225 is opened (opened). Is.

Further, the open / close detection means 302 is in the "first state" according to the present invention when the front cover 225 is closed (closed), and the open / close detecting means 302 is in the "first state" according to the present invention, and when the front cover 225 is opened (opened), the "first state" according to the present invention. It is a configuration that becomes "the state of 2".
The above-mentioned contents have a configuration when the above-mentioned modifications 2 and 3 are applied to the third embodiment.

Further, when the opening / closing detection means 302 is in the "first state" according to the present invention when the calling roller 203 and the paper feeding roller 72 are feeding the paper P, the front cover 225 is opened (opened). It is a configuration that becomes the "second state" according to the present invention.
It should be noted that the above-mentioned contents have a configuration when the above-mentioned modification 4 is applied to the third embodiment.

Further, the "first state" according to the present invention is a state in which the open / close detection switch 302-3 constituting the open / close detection means 302 is pressed, and the "second state" according to the present invention is the open / close detection switch. 302-3 is not pressed.

Further, the control operation at the start of power supply of the paper feed device 101 according to the third embodiment is read as follows in the description of the flowchart at the start of the power supply of the paper feed unit 70 according to the first embodiment shown in FIG. Just do it. That is, "control means 216" is read as "control means 216B", "insertion / removal detection switch 302-3" is read as "open / close detection switch 302-3", and "was the paper tray 71 pulled out?" It may be read as "Have the front cover 225 been opened (opened)?". As a result, a person skilled in the art can understand and carry out the third embodiment, and further description thereof will be omitted in order to avoid duplicate explanations.

As described above, according to the third embodiment, the bottom plate operation noise in the paper feed device is reduced when the image forming device returns to sleep (power supply starts for the paper feed device) after the paper runs out in the paper feed device. At the same time, it is possible to shorten the paperless confirmation time.

(Example 4)
FIG. 25 is a block diagram showing a main control configuration of the paper feeding device 101 according to the fourth embodiment. The control means 216C of the fourth embodiment is mainly different from the control means 216B of the third embodiment in that the non-volatile memory 217 is removed and the tray lower limit sensor 224 is connected.
The control means 216C raises and lowers the bottom plate 218 based on the signal for detecting the closing (closing) of the front cover 225 from the front cover switch 226 and the paper presence / absence signal on the bottom plate 218 from the paper end sensor 212. It has a function of controlling the tray raising motor 206 as described above.

The control means 216C has a front cover when power is supplied to the paper feed device 101 based on signals from the front cover switch 226, the paper end sensor 212, the tray upper limit sensor 214, the tray lower limit sensor 224, and the open / close detection switch 302-3. It has a function of controlling the tray raising motor 206 so that the first operation is performed when the 225 is not opened and the second operation is performed when the front cover 225 is opened.

Here, the first operation is an elevating operation of the bottom plate 218 that detects the presence or absence of paper on the bottom plate 218, and the second operation is the detection of the remaining amount of paper on the bottom plate 218 and the remaining amount of paper on the bottom plate 218. This is an elevating operation of the bottom plate 218 that detects the presence or absence of paper.

Regarding the operation of the paper feed device 101 according to the fourth embodiment, in FIGS. 16 to 19 explaining the operation of the paper feed device 101 of the second embodiment, "control means 216A" is read as "control means 216C" and "paper tray". "71 insertion / removal" should be read as "open / close of front cover 225", "insertion / removal detection means 302" should be read as "open / close detection means 302", and "insertion / removal detection switch 302-3" should be read as "open / close detection switch 302-3". Should be read as. As a result, those skilled in the art can understand and implement the fourth embodiment, and further description thereof will be omitted in order to avoid duplicate explanations.

As described above, according to the fourth embodiment, when there is no paper P in the paper feed device 101 and the power supply of the paper feed device 101 is started without opening the front cover 225 while the power is not supplied. The amount of movement of the bottom plate 218 can be reduced as compared with other cases, and the operation of the bottom plate at the start of power supply can be completed in a short time.

When the above-described modification 1 is applied to Examples 3 and 4, the "insertion / removal detection means 390" of the modification 1 is read as "open / close detection means 390", and the "tray insertion / removal detection switch 400" is used to open / close the front cover 225. It may be read as "front cover open / close detection switch 400" that detects the state.

When the above-mentioned modifications 2 to 4 are applied to the third and fourth embodiments, they may be read as follows. "Insert / remove of paper tray 71" should be read as "open / close of front cover 225", "tray set detection switch 202" should be read as "front cover switch 226", and "insertion / removal detection means 302" should be read as "open / close detection means 302". Further, "insertion / removal detection pin push-up part 301" is read as "open / close detection pin push-up part 301", "insertion / removal detection pin 302-1" is read as "open / close detection pin 302-1", and "insertion / removal detection switch 302". "-3" may be read as "open / close detection switch 302-3", and "control means 216 or 216A" may be read as "control means 216B or 216C".

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to such a specific embodiment, and unless otherwise specified in the above description, the present invention described in the claims. Various modifications and changes are possible within the scope of the above. For example, the technical items described in the above-described embodiments and examples may be appropriately combined.

Paper P is illustrated as a sheet that is a sheet-like recording medium on which an image is formed, but the sheet is not limited to paper P, and the sheet is not limited to paper P, and is thick paper, postcard, envelope, plain paper, thin paper, coated paper (coated paper or coated paper). Art paper, etc.), tracing paper, etc. are also included. Further, as a recording medium other than paper, any substance such as an OHP sheet, an OHP film, a resin film, etc., which has a sheet shape and can form an image may be used.

The effects appropriately described in the embodiments of the present invention merely list the most preferable effects arising from the present invention, and the effects according to the present invention are limited to those described in the embodiments of the present invention. It's not a thing.

10 Photoreceptor (image carrier)
11 Charging device 12 Exposure device 13 Developing device 70a to 70d Paper feed unit (an example of sheet feeding device)
71 Paper tray (an example of tray member)
72 Paper feed roller (an example of sheet feeding member)
100 Image forming device 101 Paper feeding device (an example of sheet feeding device)
202 Tray set detection switch 203 Call roller (an example of sheet feeding member)
206 Tray lift motor (lifting member driving means)
207 Paper feed motor (sheet feeding member driving means)
212 Paper end sensor (an example of sheet presence / absence detection means)
217 Non-volatile memory (sheet presence / absence storage means)
218 Bottom plate (an example of elevating member)
225 Front cover (an example of opening / closing member)
226 Front cover switch 302 Insertion / removal detection means, open / close detection means 302-3 Insertion / removal detection switch, open / close detection switch 390 Insertion / removal detection means, open / close detection means 400 Tray insertion / removal detection switch 410 Power supply voltage terminal 420 Ground voltage terminal 430 Switch element 440 Capacitor element P paper (example of sheet)

Japanese Unexamined Patent Publication No. 2002-284637

Claims (14)

Lifting members that can load and lower seats and
A tray member that can be inserted and removed from the device body,
Insertion / removal detection means for detecting that the tray member has been inserted / removed from the apparatus main body, and
A seat presence / absence detecting means for detecting the presence / absence of a seat on the elevating member,
A sheet presence / absence storage means for storing the sheet presence / absence detected by the sheet presence / absence detecting means is provided.
A sheet feeding device that does not raise the elevating member when there is no sheet stored in the sheet presence / absence storage means and the tray member is not removed from the apparatus main body in advance. Lifting members that can load and lower seats and
An opening and closing member that can be opened and closed with respect to the device body,
An opening / closing detecting means for detecting the opening / closing of the opening / closing member,
A seat presence / absence detecting means for detecting the presence / absence of a seat on the elevating member,
A sheet presence / absence storage means for storing the sheet presence / absence detected by the sheet presence / absence detecting means is provided.
A sheet feeding device, characterized in that the elevating member is not raised when there is no sheet stored in the sheet presence / absence storage means and the opening / closing member is not opened in advance. Lifting members that can load and lower seats and
A tray member that can be inserted and removed from the device body,
Insertion / removal detection means for detecting that the tray member has been inserted / removed from the apparatus main body, and
A seat presence / absence detecting means for detecting the presence / absence of a seat on the elevating member is provided.
The first operation is performed when the tray member is not previously removed from the device main body, and the second operation is performed when the tray member is not previously removed from the device main body. Sheet feeder. Lifting members that can load and lower seats and
An opening and closing member that can be opened and closed with respect to the device body,
An opening / closing detecting means for detecting the opening / closing of the opening / closing member,
A seat presence / absence detecting means for detecting the presence / absence of a seat on the elevating member is provided.
A sheet feeding device characterized in that a first operation is performed when the opening / closing member is not in an open state in advance, and a second operation is performed when the opening / closing member is in an open state in advance. In the sheet feeding device according to claim 3 or 4.
The first operation is an elevating member elevating operation for detecting the presence or absence of a seat on the elevating member.
The seat feeding device is characterized in that the second operation is an elevating member elevating operation for detecting the remaining amount of the seat on the elevating member and detecting the presence or absence of a seat on the elevating member. In the sheet feeding device according to claim 1 or 3,
The sheet feeding device is characterized in that the insertion / removal detecting means is in a first state when the elevating member is raised, and is in a second state when the tray member is pulled out from the device main body. In the sheet feeding device according to claim 1 or 3,
The sheet feeding is characterized in that the insertion / removal detecting means is in the first state when the tray member is inserted into the device main body, and is in the second state when the tray member is pulled out from the device main body. Feeding device. In the sheet feeding device according to claim 1 or 3,
It has a seat feeding member that feeds the seat on the elevating member.
The insertion / removal detecting means is characterized in that it is in the first state when the sheet feeding member is feeding the sheet, and is in the second state when the tray member is pulled out from the apparatus main body. Sheet feeding device. In the sheet feeding device according to claim 2 or 4.
The seat feeding device is characterized in that the open / close detecting means is in a first state when the elevating member is raised, and is in a second state when the open / close member is opened. In the sheet feeding device according to claim 2 or 4.
The sheet feeding device is characterized in that the open / close detecting means is in a first state when the open / close member is closed, and is in a second state when the open / close member is opened. In the sheet feeding device according to claim 2 or 4.
It has a seat feeding member that feeds the seat on the elevating member.
The open / close detecting means is characterized in that it is in the first state when the sheet feeding member is feeding the sheet, and is in the second state when the opening / closing member is opened. Feeding device. In the sheet feeding device according to any one of claims 6 to 11.
The first state is a state in which the switch constituting the insertion / removal detecting means or the opening / closing detecting means is pressed.
The second state is a sheet feeding device characterized in that the switch is not pressed. In the sheet feeding device according to any one of claims 6 to 12,
The insertion / removal detecting means or the opening / closing detecting means comprises an electric circuit having a switch element switchable between a power supply voltage terminal and a ground voltage terminal and a capacitor element connected to the switch element.
The first state is a state in which the switch element is connected to the power supply voltage terminal and the capacitor element is charged with the electric charge of the power supply voltage. In the second state, the switch element is grounded. A sheet feeding device connected to a voltage terminal and in a state in which the electric charge of the capacitor element is discharged to the ground voltage terminal. An image forming apparatus comprising the sheet feeding apparatus according to any one of claims 1 to 13.

Images